Ranganathan, S. and George, K. S. Tetrahedron, 1997, 53, 3347 describes the synthesis of compound (I).
Jung, M. et al. Helv. Chim. Acta, 1983, 66, 1915 and Ranganathan, S. and George, K. S. Tetrahedron, 1997, 53, 3347 disclose the synthesis of the racemic compound (II).

In WO99/05142, Shireman, B. T. and Miller, M. J. Tetrahedron Lett., 2000, 41, 9537 and in Rajappan, V. P. et al. Synth. Commun. 2001, 31, 2849 the syntheses of either the free amine or the hydrochloride salt of compound (III) are described.
